Door closer

Abstract

A door closer used with a door frame and a door panel has a hold-open device for holding the closer in any full or intermediate door-open position. The door panel is free for some manual operation independently of the closer because of a lost-motion, rotary connection between the door frame and door panel. This involves a closer shaft having a thread therein or thereon engaged by a threaded member on the closer arm so that when the member and shaft rotate relative to each other, there is also relative axial translation between them. When the hold-open device is released from some set open position after some manual, door panel closing motion, the shaft revolves, causing some originally abutting but separated facing surfaces on the member and the shaft axially to approach each other and finally and again to abut, thus taking out the lost motion and causing the closer to move the door panel from substantially fully open or any intermediate open position into fully closed position.

I claim: 
     
       1. A door closer for use with a door frame and a door panel comprising a housing, a shaft having a thread, means mounting said shaft to rotate about an axis in said housing, means constraining said shaft against axial movement relative to said housing, means interconnecting said door frame and said door panel through said housing and said shaft, said interconnecting means including a member engaging said thread and movable axially of said shaft, and means on said shaft and on said member for limiting axial movement of said member and said shaft. 
     
     
       2. A device as in claim 1 including means in said housing for restricting rotation of said shaft in said housing. 
     
     
       3. A device as in claim 1 in which said limiting means includes a surface on said member and a surface on said shaft adapted to abut in a plane substantially normal to said axis. 
     
     
       4. A device as in claim 3 in which the angle of said thread precludes wedging said surfaces together. 
     
     
       5. A device as in claim 3 in which said surfaces abut when said panel and said frame are substantially in a predetermined position of said door panel relative to said door frame. 
     
     
       6. A device as in claim 3 in which said surfaces are axially spaced apart when said panel and said frame are in any position relative to each other and away from a predetermined open position relative to each other. 
     
     
       7. A device as in claim 3 including means for reducing friction between said surfaces. 
     
     
       8. In a door closer, a housing, a shaft, means for mounting said shaft to rotate about an axis in said housing, an actuating arm, and means for mounting said actuating arm on said shaft for combined rotary and axial motion relative thereto. 
     
     
       9. A device as in claim 8 including means for limiting said combined rotary and axial motion in one relative axial position of said arm and said shaft. 
     
     
       10. A device as in claim 9 including means for changing said axial position. 
     
     
       11. In a door closer having a housing, a shaft having an axis, means for constraining said shaft to rotation in said housing about said axis and against translation along said axis, a closer arm, and means for mounting said closer arm on said shaft for rotation relative to said shaft about said axis and for movement axially of said shaft. 
     
     
       12. A device as in claim 11 in which said rotation and said movememt axailly are concurrent. 
     
     
       13. A device as in claim 11 in which said mounting means includes a first incline on said shaft helical about said axis, and a second incline on said arm helical about said axis and engaging said first incline. 
     
     
       14. A device as in claim 13 in which said inclines are threads. 
     
     
       15. A device as in claim 13 including means on said shaft and on said arm defining surfaces substantially normal to said axis and movable toward and away from abutment with each other upon relative rotation of said arm and said shaft. 
     
     
       16. A device as in claim 13 in which said inclines are pitched to urge said surfaces toward abutment when said door panel is moved toward open position relative to said frame.